For some reason I have an extra unneeded language installed on my system (more precisely, $LANGUAGE variable is ru:en_CA:en where supposed to be ru:en, and also apt tries to load addresses like http://ppa.launchpad.net precise/main Translation-en_CA).

2 Answers
2

I would rather recommend using the standard GUI apps to do this. With Language Selector you can drag en_CA out of the list of languages (i.e. below the 'English' entry), and that should remove it from your LANGUAGE variable without having to manually edit system files.

You'll then need to log out and log back into your session for the changes to take effect.